Radiation detector and method for operating a radiation detector

ABSTRACT

A radiation detector is disclosed. The radiation detector includes a sensor unit having a plurality of sensor elements for generating a sensor signal; an evaluation unit having a plurality of evaluation elements for evaluating and converting the sensor signal into an output signal; and a signal processing unit directly following the evaluation unit for processing the output signal, each evaluation element being connected to an associated sensor element via a respective electrical interconnect element including an interconnect capacitance and an individual length. The interconnect capacitances are different and as a result lead to different signal properties being exhibited by the output signals. At least some of the evaluation elements including an additional actuating element, the actuating elements of different evaluation elements being different from one another and being chosen such that the different signal properties of the output signals are aligned.

PRIORITY STATEMENT

The present application hereby claims priority under 35 U.S.C. § 119 toEuropean patent application number EP17177142.1 filed Jun. 21, 2017, theentire contents of which are hereby incorporated herein by reference.

FIELD

At least one embodiment of the invention generally relates to aradiation detector and/or to a method for operating a radiationdetector.

BACKGROUND

Imaging devices in the medical diagnostics field, in particular indiagnostic radiology, typically comprise a radiation detector, inparticular an X-ray radiation detector, or X-ray detector for short.Imaging devices are generally understood in the present context to meanX-ray machines and specifically computed tomography systems.

X-ray detectors are usually embodied as scintillator detectors or asphoton-counting detectors having a direct converter.

Scintillator detectors comprise a scintillator material. Scintillatormaterials are excited as a result of being irradiated with X-rayradiation and emit the excitation energy in the form of light. Theemitted light is subsequently converted, for example via sensor elementsembodied as photodiodes, into an electrical sensor signal to produce anoutput signal, in particular into an electrical current, also known as asignal current, and evaluated in an evaluation unit, the latter usuallycomprising a plurality of evaluation elements. To that end, eachevaluation element usually includes an application-specific integratedcircuit (ASIC). The output signal may also have a current pulse, forexample, though such current pulses occur only in the case ofphoton-counting direct converters.

Scintillator detectors frequently comprise a plurality of scintillatorelements which are arranged in the manner of an array. Analogously, thesensor elements and the evaluation elements likewise comprise anarrangement in the manner of an array.

Radiation detectors having direct converters usually contain asemiconductor material, for example a semiconductor based on cadmiumtelluride (CdTe), which converts incident radiation, for example X-rayradiation, into an electrical output signal, in particular into acurrent pulse.

The two types of detector in each case feature a matrix-likearrangement, both of the sensor elements and of the evaluation elements.In this connection, the sensor elements are also referred to as sensorpixels and the evaluation elements as evaluation pixels.

In order to evaluate the signal currents, a sensor element typically hasan electrical connection to an evaluation element associated with it viaan electrical interconnect element, for example an electrical lineelement. The signal currents are typically evaluated in the evaluationunit to produce an output signal and converted, into an image, forexample, in a signal processing unit that usually directly follows theevaluation unit.

Because small currents are often evaluated via the evaluation unit andelectrical lines typically exhibit parasitic effects, for exampleparasitic capacitances, the sensor unit and the evaluation unit arefrequently embodied as coextensive in area and are arranged one placedon top of the other in order to keep the length of the electricalinterconnect elements to a minimum. By small currents, in the presentcontext, are understood electrical currents having a value in the rangefrom 1 pA to 1 μA (per evaluation element). In order to evaluate suchsmall signal currents, each evaluation element typically comprises inaddition for example an amplifier unit for amplifying the signalcurrents and consequently also for amplifying the output signal.

Coextensive embodiment is understood in the present context to mean thatthe sensor unit and the evaluation unit in each case have a length and awidth which each have an equal value, except for a tolerance of <20%, inparticular <10%. This applies analogously to the number and distributionof the individual elements (sensor elements and evaluation elements), aswell as to a surface area profile, for example in the shape of arectangle, of the elements (sensor elements and evaluation elements).Furthermore, the sensor unit and the evaluation unit are arranged one ontop of the other in a form-fitting manner. This ensures that each sensorelement has associated with it an evaluation element which is disposed“opposite” the sensor element. The length of the electrical connectionbetween a sensor element and its associated evaluation element isreduced as a result. In particular, the already mentioned shortestpossible electrical connection between the sensor elements and theevaluation elements is guaranteed by this configuration.

SUMMARY

The inventors have discover that, as a result of the short electricalconnection, the latter typically exhibits minimal parasitic effects,since there is a progressive correlation in particular between a lengthof an electrical line and the magnitude of parasitic effects.Progressive correlation is understood in the present context to meanthat as a value for a length of an electrical connection, in particularan electrical line, increases, parasitic effects occurring in the line,for example the value of a parasitic capacitance of the electrical line,likewise exhibit an increasing progression.

In particular, the inventors have discover that the evaluation unitoften has a disadvantageous area ratio between a total surface area ofthe evaluation unit and a surface area of the evaluation unit that is“actively” used by evaluation elements. By this is understood in thepresent context that a large part of the surface area of the evaluationunit is not used in accordance with the actual purpose of the evaluationunit from the circuit layout standpoint. This leads to an undesirablydisadvantageous element density. Element density is understood in thepresent context to mean a number of elements (sensor elements andevaluation element) in relation to a surface area on which the elements(sensor elements and evaluation element) are arranged.

In order to counteract this disadvantageous area ratio, the evaluationunit has a surface area which is formed exclusively by the individualsurface areas of the evaluation elements. The total surface area of theevaluation unit is reduced as a result to the sum of the surface areasof the evaluation elements. Usually, therefore, the evaluation unit hasno area that is “unused” in terms of circuit layout, except formanufacturing-related tolerances.

Consequently, the total surface area of the evaluation unit has asmaller value than the total surface area of the sensor unit. In otherwords, the sensor unit and the evaluation unit are not coextensive inarea in the present instance. As a result, at least some of theelectrical connections between the individual sensor elements and theassociated evaluation elements, in particular in a peripheral region ofthe sensor and evaluation unit, have a different length.

Due to the different lengths of the electrical connections, theinventors have discover that the occurring parasitic effects, inparticular the occurring parasitic capacitances, have different values.This has a disadvantageous impact on for example a pulse shape of theelectrical output signal, a noise of the amplified output signal, and inparticular a uniformity of the noise across the individual evaluationelements. Consequently, this also disadvantageously affects the imagequality of the radiation detector. Effects of such kind, for example thealready cited noise, lead for example to an uneven image quality andtherefore detract from the diagnostic value of the acquired X-rayimages.

At least one embodiment of the invention discloses a radiation detectorin which artifacts due to such parasitic effects are at least reduced.

At least one embodiment of the invention is directed to a radiationdetector, in particular an X-ray detector; and/or a method for operatinga radiation detector.

Advantageous embodiments, developments and variants are the subjectmatter of the claims.

The advantages cited with regard to the radiation detector and thepreferred embodiments are to be applied analogously to the method, andvice versa.

The radiation detector of at least one embodiment comprises a sensorunit having a plurality of sensor elements for generating a sensorsignal. In addition, the radiation detector comprises an evaluation unithaving a plurality of evaluation elements. In this arrangement, thenumber of sensor elements preferably corresponds to the number ofevaluation elements. By way of the evaluation elements it is madepossible to evaluate the sensor signal and to convert the sensor signalinto an output signal. In order to process the output signal, theradiation detector additionally comprises a signal processing unitdirectly following the evaluation unit.

Each evaluation element is associated with a sensor element and for thispurpose is connected in an electrically conductive manner to therespective associated sensor element via an electrical interconnectelement, for example an electrical line. The electrical interconnectelements take the form for example of an electrical line composed ofstrands, preferably a conductor track on a printed circuit board. Theelectrical interconnect element has an interconnect capacitance, forexample a parasitic capacitance, as well as an individual length.Interconnect capacitance is generally understood in the present contextto mean for example a capacitance per unit length, a fringe capacitanceand/or a parasitic capacitance.

At least one embodiment of the invention is directed to a method foroperating a radiation detector.

BRIEF DESCRIPTION OF THE DRAWINGS

Example embodiments of the invention are explained in more detail belowwith reference to the figures. These show, in some cases in greatlysimplified representations:

FIG. 1 a cross-sectional view of a sensor unit arranged opposite anevaluation unit inside a radiation detector,

FIG. 2 a greatly simplified block diagram of a circuit of a radiationdetector according to a first embodiment, and

FIG. 3 a greatly simplified block diagram of a circuit of a radiationdetector according to a second embodiment.

In the figures, like-acting parts are labeled with the same referencesigns.

DETAILED DESCRIPTION OF THE EXAMPLE EMBODIMENTS

The drawings are to be regarded as being schematic representations andelements illustrated in the drawings are not necessarily shown to scale.Rather, the various elements are represented such that their functionand general purpose become apparent to a person skilled in the art. Anyconnection or coupling between functional blocks, devices, components,or other physical or functional units shown in the drawings or describedherein may also be implemented by an indirect connection or coupling. Acoupling between components may also be established over a wirelessconnection. Functional blocks may be implemented in hardware, firmware,software, or a combination thereof.

Various example embodiments will now be described more fully withreference to the accompanying drawings in which only some exampleembodiments are shown. Specific structural and functional detailsdisclosed herein are merely representative for purposes of describingexample embodiments. Example embodiments, however, may be embodied invarious different forms, and should not be construed as being limited toonly the illustrated embodiments. Rather, the illustrated embodimentsare provided as examples so that this disclosure will be thorough andcomplete, and will fully convey the concepts of this disclosure to thoseskilled in the art. Accordingly, known processes, elements, andtechniques, may not be described with respect to some exampleembodiments. Unless otherwise noted, like reference characters denotelike elements throughout the attached drawings and written description,and thus descriptions will not be repeated. The present invention,however, may be embodied in many alternate forms and should not beconstrued as limited to only the example embodiments set forth herein.

It will be understood that, although the terms first, second, etc. maybe used herein to describe various elements, components, regions,layers, and/or sections, these elements, components, regions, layers,and/or sections, should not be limited by these terms. These terms areonly used to distinguish one element from another. For example, a firstelement could be termed a second element, and, similarly, a secondelement could be termed a first element, without departing from thescope of example embodiments of the present invention. As used herein,the term “and/or,” includes any and all combinations of one or more ofthe associated listed items. The phrase “at least one of” has the samemeaning as “and/or”.

Spatially relative terms, such as “beneath,” “below,” “lower,” “under,”“above,” “upper,” and the like, may be used herein for ease ofdescription to describe one element or feature's relationship to anotherelement(s) or feature(s) as illustrated in the figures. It will beunderstood that the spatially relative terms are intended to encompassdifferent orientations of the device in use or operation in addition tothe orientation depicted in the figures. For example, if the device inthe figures is turned over, elements described as “below,” “beneath,” or“under,” other elements or features would then be oriented “above” theother elements or features. Thus, the example terms “below” and “under”may encompass both an orientation of above and below. The device may beotherwise oriented (rotated 90 degrees or at other orientations) and thespatially relative descriptors used herein interpreted accordingly. Inaddition, when an element is referred to as being “between” twoelements, the element may be the only element between the two elements,or one or more other intervening elements may be present.

Spatial and functional relationships between elements (for example,between modules) are described using various terms, including“connected,” “engaged,” “interfaced,” and “coupled.” Unless explicitlydescribed as being “direct,” when a relationship between first andsecond elements is described in the above disclosure, that relationshipencompasses a direct relationship where no other intervening elementsare present between the first and second elements, and also an indirectrelationship where one or more intervening elements are present (eitherspatially or functionally) between the first and second elements. Incontrast, when an element is referred to as being “directly” connected,engaged, interfaced, or coupled to another element, there are nointervening elements present. Other words used to describe therelationship between elements should be interpreted in a like fashion(e.g., “between,” versus “directly between,” “adjacent,” versus“directly adjacent,” etc.).

The terminology used herein is for the purpose of describing particularembodiments only and is not intended to be limiting of exampleembodiments of the invention. As used herein, the singular forms “a,”“an,” and “the,” are intended to include the plural forms as well,unless the context clearly indicates otherwise. As used herein, theterms “and/or” and “at least one of” include any and all combinations ofone or more of the associated listed items. It will be furtherunderstood that the terms “comprises,” “comprising,” “includes,” and/or“including,” when used herein, specify the presence of stated features,integers, steps, operations, elements, and/or components, but do notpreclude the presence or addition of one or more other features,integers, steps, operations, elements, components, and/or groupsthereof. As used herein, the term “and/or” includes any and allcombinations of one or more of the associated listed items. Expressionssuch as “at least one of,” when preceding a list of elements, modify theentire list of elements and do not modify the individual elements of thelist. Also, the term “exemplary” is intended to refer to an example orillustration.

When an element is referred to as being “on,” “connected to,” “coupledto,” or “adjacent to,” another element, the element may be directly on,connected to, coupled to, or adjacent to, the other element, or one ormore other intervening elements may be present. In contrast, when anelement is referred to as being “directly on,” “directly connected to,”“directly coupled to,” or “immediately adjacent to,” another elementthere are no intervening elements present.

It should also be noted that in some alternative implementations, thefunctions/acts noted may occur out of the order noted in the figures.For example, two figures shown in succession may in fact be executedsubstantially concurrently or may sometimes be executed in the reverseorder, depending upon the functionality/acts involved.

Unless otherwise defined, all terms (including technical and scientificterms) used herein have the same meaning as commonly understood by oneof ordinary skill in the art to which example embodiments belong. Itwill be further understood that terms, e.g., those defined in commonlyused dictionaries, should be interpreted as having a meaning that isconsistent with their meaning in the context of the relevant art andwill not be interpreted in an idealized or overly formal sense unlessexpressly so defined herein.

Before discussing example embodiments in more detail, it is noted thatsome example embodiments may be described with reference to acts andsymbolic representations of operations (e.g., in the form of flowcharts, flow diagrams, data flow diagrams, structure diagrams, blockdiagrams, etc.) that may be implemented in conjunction with units and/ordevices discussed in more detail below. Although discussed in aparticularly manner, a function or operation specified in a specificblock may be performed differently from the flow specified in aflowchart, flow diagram, etc. For example, functions or operationsillustrated as being performed serially in two consecutive blocks mayactually be performed simultaneously, or in some cases be performed inreverse order. Although the flowcharts describe the operations assequential processes, many of the operations may be performed inparallel, concurrently or simultaneously. In addition, the order ofoperations may be re-arranged. The processes may be terminated whentheir operations are completed, but may also have additional steps notincluded in the figure. The processes may correspond to methods,functions, procedures, subroutines, subprograms, etc.

Specific structural and functional details disclosed herein are merelyrepresentative for purposes of describing example embodiments of thepresent invention. This invention may, however, be embodied in manyalternate forms and should not be construed as limited to only theembodiments set forth herein.

Units and/or devices according to one or more example embodiments may beimplemented using hardware, software, and/or a combination thereof. Forexample, hardware devices may be implemented using processing circuitysuch as, but not limited to, a processor, Central Processing Unit (CPU),a controller, an arithmetic logic unit (ALU), a digital signalprocessor, a microcomputer, a field programmable gate array (FPGA), aSystem-on-Chip (SoC), a programmable logic unit, a microprocessor, orany other device capable of responding to and executing instructions ina defined manner. Portions of the example embodiments and correspondingdetailed description may be presented in terms of software, oralgorithms and symbolic representations of operation on data bits withina computer memory. These descriptions and representations are the onesby which those of ordinary skill in the art effectively convey thesubstance of their work to others of ordinary skill in the art. Analgorithm, as the term is used here, and as it is used generally, isconceived to be a self-consistent sequence of steps leading to a desiredresult. The steps are those requiring physical manipulations of physicalquantities. Usually, though not necessarily, these quantities take theform of optical, electrical, or magnetic signals capable of beingstored, transferred, combined, compared, and otherwise manipulated. Ithas proven convenient at times, principally for reasons of common usage,to refer to these signals as bits, values, elements, symbols,characters, terms, numbers, or the like.

It should be borne in mind, however, that all of these and similar termsare to be associated with the appropriate physical quantities and aremerely convenient labels applied to these quantities. Unlessspecifically stated otherwise, or as is apparent from the discussion,terms such as “processing” or “computing” or “calculating” or“determining” of “displaying” or the like, refer to the action andprocesses of a computer system, or similar electronic computingdevice/hardware, that manipulates and transforms data represented asphysical, electronic quantities within the computer system's registersand memories into other data similarly represented as physicalquantities within the computer system memories or registers or othersuch information storage, transmission or display devices.

In this application, including the definitions below, the term ‘module’or the term ‘controller’ may be replaced with the term ‘circuit.’ Theterm ‘module’ may refer to, be part of, or include processor hardware(shared, dedicated, or group) that executes code and memory hardware(shared, dedicated, or group) that stores code executed by the processorhardware.

The module may include one or more interface circuits. In some examples,the interface circuits may include wired or wireless interfaces that areconnected to a local area network (LAN), the Internet, a wide areanetwork (WAN), or combinations thereof. The functionality of any givenmodule of the present disclosure may be distributed among multiplemodules that are connected via interface circuits. For example, multiplemodules may allow load balancing. In a further example, a server (alsoknown as remote, or cloud) module may accomplish some functionality onbehalf of a client module.

Software may include a computer program, program code, instructions, orsome combination thereof, for independently or collectively instructingor configuring a hardware device to operate as desired. The computerprogram and/or program code may include program or computer-readableinstructions, software components, software modules, data files, datastructures, and/or the like, capable of being implemented by one or morehardware devices, such as one or more of the hardware devices mentionedabove. Examples of program code include both machine code produced by acompiler and higher level program code that is executed using aninterpreter.

For example, when a hardware device is a computer processing device(e.g., a processor, Central Processing Unit (CPU), a controller, anarithmetic logic unit (ALU), a digital signal processor, amicrocomputer, a microprocessor, etc.), the computer processing devicemay be configured to carry out program code by performing arithmetical,logical, and input/output operations, according to the program code.Once the program code is loaded into a computer processing device, thecomputer processing device may be programmed to perform the programcode, thereby transforming the computer processing device into a specialpurpose computer processing device. In a more specific example, when theprogram code is loaded into a processor, the processor becomesprogrammed to perform the program code and operations correspondingthereto, thereby transforming the processor into a special purposeprocessor.

Software and/or data may be embodied permanently or temporarily in anytype of machine, component, physical or virtual equipment, or computerstorage medium or device, capable of providing instructions or data to,or being interpreted by, a hardware device. The software also may bedistributed over network coupled computer systems so that the softwareis stored and executed in a distributed fashion. In particular, forexample, software and data may be stored by one or more computerreadable recording mediums, including the tangible or non-transitorycomputer-readable storage media discussed herein.

Even further, any of the disclosed methods may be embodied in the formof a program or software. The program or software may be stored on anon-transitory computer readable medium and is adapted to perform anyone of the aforementioned methods when run on a computer device (adevice including a processor). Thus, the non-transitory, tangiblecomputer readable medium, is adapted to store information and is adaptedto interact with a data processing facility or computer device toexecute the program of any of the above mentioned embodiments and/or toperform the method of any of the above mentioned embodiments.

Example embodiments may be described with reference to acts and symbolicrepresentations of operations (e.g., in the form of flow charts, flowdiagrams, data flow diagrams, structure diagrams, block diagrams, etc.)that may be implemented in conjunction with units and/or devicesdiscussed in more detail below. Although discussed in a particularlymanner, a function or operation specified in a specific block may beperformed differently from the flow specified in a flowchart, flowdiagram, etc. For example, functions or operations illustrated as beingperformed serially in two consecutive blocks may actually be performedsimultaneously, or in some cases be performed in reverse order.

According to one or more example embodiments, computer processingdevices may be described as including various functional units thatperform various operations and/or functions to increase the clarity ofthe description. However, computer processing devices are not intendedto be limited to these functional units. For example, in one or moreexample embodiments, the various operations and/or functions of thefunctional units may be performed by other ones of the functional units.Further, the computer processing devices may perform the operationsand/or functions of the various functional units without sub-dividingthe operations and/or functions of the computer processing units intothese various functional units.

Units and/or devices according to one or more example embodiments mayalso include one or more storage devices. The one or more storagedevices may be tangible or non-transitory computer-readable storagemedia, such as random access memory (RAM), read only memory (ROM), apermanent mass storage device (such as a disk drive), solid state (e.g.,NAND flash) device, and/or any other like data storage mechanism capableof storing and recording data. The one or more storage devices may beconfigured to store computer programs, program code, instructions, orsome combination thereof, for one or more operating systems and/or forimplementing the example embodiments described herein. The computerprograms, program code, instructions, or some combination thereof, mayalso be loaded from a separate computer readable storage medium into theone or more storage devices and/or one or more computer processingdevices using a drive mechanism. Such separate computer readable storagemedium may include a Universal Serial Bus (USB) flash drive, a memorystick, a Blu-ray/DVD/CD-ROM drive, a memory card, and/or other likecomputer readable storage media. The computer programs, program code,instructions, or some combination thereof, may be loaded into the one ormore storage devices and/or the one or more computer processing devicesfrom a remote data storage device via a network interface, rather thanvia a local computer readable storage medium. Additionally, the computerprograms, program code, instructions, or some combination thereof, maybe loaded into the one or more storage devices and/or the one or moreprocessors from a remote computing system that is configured to transferand/or distribute the computer programs, program code, instructions, orsome combination thereof, over a network. The remote computing systemmay transfer and/or distribute the computer programs, program code,instructions, or some combination thereof, via a wired interface, an airinterface, and/or any other like medium.

The one or more hardware devices, the one or more storage devices,and/or the computer programs, program code, instructions, or somecombination thereof, may be specially designed and constructed for thepurposes of the example embodiments, or they may be known devices thatare altered and/or modified for the purposes of example embodiments.

A hardware device, such as a computer processing device, may run anoperating system (OS) and one or more software applications that run onthe OS. The computer processing device also may access, store,manipulate, process, and create data in response to execution of thesoftware. For simplicity, one or more example embodiments may beexemplified as a computer processing device or processor; however, oneskilled in the art will appreciate that a hardware device may includemultiple processing elements or processors and multiple types ofprocessing elements or processors. For example, a hardware device mayinclude multiple processors or a processor and a controller. Inaddition, other processing configurations are possible, such as parallelprocessors.

The computer programs include processor-executable instructions that arestored on at least one non-transitory computer-readable medium (memory).The computer programs may also include or rely on stored data. Thecomputer programs may encompass a basic input/output system (BIOS) thatinteracts with hardware of the special purpose computer, device driversthat interact with particular devices of the special purpose computer,one or more operating systems, user applications, background services,background applications, etc. As such, the one or more processors may beconfigured to execute the processor executable instructions.

The computer programs may include: (i) descriptive text to be parsed,such as HTML (hypertext markup language) or XML (extensible markuplanguage), (ii) assembly code, (iii) object code generated from sourcecode by a compiler, (iv) source code for execution by an interpreter,(v) source code for compilation and execution by a just-in-timecompiler, etc. As examples only, source code may be written using syntaxfrom languages including C, C++, C#, Objective-C, Haskell, Go, SQL, R,Lisp, Java®, Fortran, Perl, Pascal, Curl, OCaml, Javascript®, HTML5,Ada, ASP (active server pages), PHP, Scala, Eiffel, Smalltalk, Erlang,Ruby, Flash®, Visual Basic®, Lua, and Python®.

Further, at least one embodiment of the invention relates to thenon-transitory computer-readable storage medium including electronicallyreadable control information (processor executable instructions) storedthereon, configured in such that when the storage medium is used in acontroller of a device, at least one embodiment of the method may becarried out.

The computer readable medium or storage medium may be a built-in mediuminstalled inside a computer device main body or a removable mediumarranged so that it can be separated from the computer device main body.The term computer-readable medium, as used herein, does not encompasstransitory electrical or electromagnetic signals propagating through amedium (such as on a carrier wave); the term computer-readable medium istherefore considered tangible and non-transitory. Non-limiting examplesof the non-transitory computer-readable medium include, but are notlimited to, rewriteable non-volatile memory devices (including, forexample flash memory devices, erasable programmable read-only memorydevices, or a mask read-only memory devices); volatile memory devices(including, for example static random access memory devices or a dynamicrandom access memory devices); magnetic storage media (including, forexample an analog or digital magnetic tape or a hard disk drive); andoptical storage media (including, for example a CD, a DVD, or a Blu-rayDisc). Examples of the media with a built-in rewriteable non-volatilememory, include but are not limited to memory cards; and media with abuilt-in ROM, including but not limited to ROM cassettes; etc.Furthermore, various information regarding stored images, for example,property information, may be stored in any other form, or it may beprovided in other ways.

The term code, as used above, may include software, firmware, and/ormicrocode, and may refer to programs, routines, functions, classes, datastructures, and/or objects. Shared processor hardware encompasses asingle microprocessor that executes some or all code from multiplemodules. Group processor hardware encompasses a microprocessor that, incombination with additional microprocessors, executes some or all codefrom one or more modules. References to multiple microprocessorsencompass multiple microprocessors on discrete dies, multiplemicroprocessors on a single die, multiple cores of a singlemicroprocessor, multiple threads of a single microprocessor, or acombination of the above.

Shared memory hardware encompasses a single memory device that storessome or all code from multiple modules. Group memory hardwareencompasses a memory device that, in combination with other memorydevices, stores some or all code from one or more modules.

The term memory hardware is a subset of the term computer-readablemedium. The term computer-readable medium, as used herein, does notencompass transitory electrical or electromagnetic signals propagatingthrough a medium (such as on a carrier wave); the term computer-readablemedium is therefore considered tangible and non-transitory. Non-limitingexamples of the non-transitory computer-readable medium include, but arenot limited to, rewriteable non-volatile memory devices (including, forexample flash memory devices, erasable programmable read-only memorydevices, or a mask read-only memory devices); volatile memory devices(including, for example static random access memory devices or a dynamicrandom access memory devices); magnetic storage media (including, forexample an analog or digital magnetic tape or a hard disk drive); andoptical storage media (including, for example a CD, a DVD, or a Blu-rayDisc). Examples of the media with a built-in rewriteable non-volatilememory, include but are not limited to memory cards; and media with abuilt-in ROM, including but not limited to ROM cassettes; etc.Furthermore, various information regarding stored images, for example,property information, may be stored in any other form, or it may beprovided in other ways.

The apparatuses and methods described in this application may bepartially or fully implemented by a special purpose computer created byconfiguring a general purpose computer to execute one or more particularfunctions embodied in computer programs. The functional blocks andflowchart elements described above serve as software specifications,which can be translated into the computer programs by the routine workof a skilled technician or programmer.

Although described with reference to specific examples and drawings,modifications, additions and substitutions of example embodiments may bevariously made according to the description by those of ordinary skillin the art. For example, the described techniques may be performed in anorder different with that of the methods described, and/or componentssuch as the described system, architecture, devices, circuit, and thelike, may be connected or combined to be different from theabove-described methods, or results may be appropriately achieved byother components or equivalents.

The radiation detector of at least one embodiment comprises a sensorunit having a plurality of sensor elements for generating a sensorsignal. In addition, the radiation detector comprises an evaluation unithaving a plurality of evaluation elements. In this arrangement, thenumber of sensor elements preferably corresponds to the number ofevaluation elements. By way of the evaluation elements it is madepossible to evaluate the sensor signal and to convert the sensor signalinto an output signal. In order to process the output signal, theradiation detector additionally comprises a signal processing unitdirectly following the evaluation unit.

Each evaluation element is associated with a sensor element and for thispurpose is connected in an electrically conductive manner to therespective associated sensor element via an electrical interconnectelement, for example an electrical line. The electrical interconnectelements take the form for example of an electrical line composed ofstrands, preferably a conductor track on a printed circuit board. Theelectrical interconnect element has an interconnect capacitance, forexample a parasitic capacitance, as well as an individual length.Interconnect capacitance is generally understood in the present contextto mean for example a capacitance per unit length, a fringe capacitanceand/or a parasitic capacitance.

By parasitic capacitance is generally understood an in most casesundesirable capacitance between two electrical line elements which, dueto their charge and the distance separating them, exhibit a capacitancein the manner of a parallel-plate capacitor, which capacitance has an(electrically) disruptive effect. What is specifically understood byinterconnect capacitance is in particular a parasitic capacitance ofalready cited type between the electrical interconnect elements.

Generally, individual capacitances of lines are characterized by aplurality of different capacitances, for example capacitances to groundand/or capacitances to other lines. With regard to at least oneembodiment of the invention, in particular the parasitic capacitances toground and parasitic capacitances to immediately neighboring lineelements of a respective line element are relevant. By ground, in thepresent context, is generally understood the electrical zero potential.

As described in the introduction, the surface area of the sensor unit ofthe radiation detector has a different, in particular greater, valuethan the surface area of the evaluation unit. As a result thereof, theelectrical interconnect elements have different, individual lengths,depending on a position of the sensor and evaluation elements that areinterconnected by them. Preferably, the electrical interconnect elementshave a length with a value in the range between 10 μm and 300 μm in acentral region of the sensor unit and the evaluation unit, and a valuein the range between 1 mm and 4 cm in a peripheral region of the sensorunit and the evaluation unit. In particular, both the sensor unit andthe evaluation unit have a shape in the manner of a planar rectangle.Planar is to be understood in the present context to mean a plate-shapedembodiment. For reasons of symmetry and easier manufacture, at leastsome of the electrical interconnect elements have the same length, forexample.

Furthermore, the value of the interconnect capacitance, in particularthe value of the parasitic capacitance, is progressively correlated withthe value of the length of the electrical interconnect element. In thisrespect, due to the different, individual lengths of the electricalinterconnect elements, the interconnect capacitances of at least some ofthe electrical interconnect elements have a different value in eachcase. In other words, due to their different, individual lengths, atleast some of the electrical interconnect elements have a differentinterconnect capacitance in each case.

Due to their different values, the different interconnect capacitancesdisrupt the output signals transmitted via the electrical interconnectelements, as a result of which the output signals exhibit differentsignal properties. Signal properties are understood in the presentcontext specifically to mean a pulse shape (in particular a pulse widthand a pulse height) and/or a noise of the output signals. Furthermore,the additional interconnect capacitance influences the noise of theoutput signal amplified via the amplifier unit.

Furthermore, at least some of the evaluation elements have an additionalactuating element, for example a capacitance, the actuating elements ofdifferent evaluation elements being different from one another. Theactuating elements are chosen such that the signal properties of theoutput signals transferred from the evaluation unit to the signalprocessing unit (the signal properties varying as a function of thedifferent interconnect capacitances) are aligned.

In other words, in order to achieve a homogeneous response behavior ofthe evaluation unit, in particular with regard to the already describedsignal properties (for example the pulse width) and/or the noise of theoutput signal, it has proven advantageous to align the differentinterconnect capacitances in such a way that the different electricalinterconnect elements preferably have an identical total capacitance.Response behavior is generally understood in the present context to meana change to a signal that occurs due to a processing step, for exampleon the basis of a transmission function, inside a signal processingcomponent (specifically, in the present case, a respective evaluationelement).

This means that after the alignment each electrical interconnectelement, irrespective of its length, has the same interconnectcapacitance (the rule that applies in this case is: interconnectcapacitance=total capacitance). In order to achieve a total capacitancevalue of such kind, the actuating elements of the different electricalinterconnect elements each preferably have a balancing capacitance valuecorresponding to a difference between the total capacitance and therespective interconnect capacitance of the electrical interconnectelement.

Owing to the fact that only an extension, in particular an increase, ina value of the different interconnect capacitances is made possible viathe actuating elements, the electrical interconnect element whoseinterconnect capacitance has the greatest value serves as a minimumvalue for the value of the total capacitance.

The following example is intended to aid a better understanding:

A radiation detector comprises three sensor elements and threeevaluation elements. One sensor element in each case is electricallyconnected to an evaluation element via an electrical interconnectelement. In this respect, the radiation detector comprises threeelectrical interconnect elements, each of which has a different,individual length. Due to the different lengths of the electricalinterconnect elements, these each have different interconnectcapacitances. A first electrical interconnect element has aninterconnect capacitance with a value of 200 fF, a second electricalinterconnect element has an interconnect capacitance with a value of 350fF, and a third electrical interconnect element has an interconnectcapacitance with a value of 500 fF. The value of the total capacitanceis therefore determined by the third electrical interconnectelement—because, of all three interconnect capacitances, this has thehighest value—as equal to a value (minimum value) of at least 500 fF.This value of 500 fF, for example, is defined as the value for the totalcapacitance. In order to align the different interconnect capacitancesof the electrical interconnect elements to the total capacitance, thethree electrical interconnect elements each have an actuating elementhaving a balancing capacitance. The actuating element of the firstelectrical interconnect element has a balancing capacitance with a valueof 300 fF (difference between total capacitance value and interconnectcapacitance value: 500 fF−200 fF=300 fF). The actuating element of thesecond electrical interconnect element has a balancing capacitance witha value of 150 fF (difference between total capacitance value andinterconnect capacitance value: 500 fF−350 fF=150 fF).

In particular an alignment of the signal properties of the outputsignals is achieved via the actuating elements, which has provenadvantageous with regard to the image quality of the radiation detector.Furthermore, effects degrading image quality are preempted by way of thealignment, in particular the homogenization, of the signal properties ofthe output signals. In the present case, such effects are referred to asthe pile-up effect and/or the paralysis effect. By pile-up effect, inthe present context, is understood an effect in which, for example, twosquare-wave signal pulses touch each other on sides facing toward eachother in such a way that a signal processing unit detects the two signalpulses as a single signal pulse having an overall duration of the twoindividual pulses. By the paralysis effect, in the present context, isunderstood the effect in which a counter unit of the detector missespulses to be counted due to an overlapping of the pulses, for exampledue to the pile-up effect. While the counter unit “counts” a pulse, itis “paralyzed” for further count events, as a result of which fewerpulses are counted than actually occur as events.

The paralysis effect occurs in particular at high pulse frequencies.High pulse frequencies are understood in the present context to meanfrequencies of pulses at which an average gap between two pulses has asmaller value than, for example, ten times an average full width at halfmaximum of one pulse.

Particularly preferably, at least some of the additional actuatingelements have a different balancing capacitance. The advantage is thatby this, it is a simple exercise, considered from the circuit layoutstandpoint, to achieve a balancing of the interconnect capacitances inthe electrical interconnect elements in the manner already described.

In a beneficial embodiment, in order to match the actuating elements tothe different values of the interconnect capacitances, in particular theparasitic capacitances, the actuating elements are adjustable in termsof their value. By adjustable, in the present context, is understoodthat the actuating elements have a variable balancing capacitance value,at least, for example, during the course of an installation into theradiation detector.

In a beneficial embodiment, each evaluation element comprises anapplication-specific integrated circuit (ASIC) having an amplifierelement. The advantage of the embodiment lies in the fact that anexplicitly application-specific circuit for evaluating the sensor signalis realized via the ASIC. By this, it is made possible in particular tointegrate specific properties and/or application details of theradiation detector, for example the type of radiation detector(scintillator detector or direct-converting detector) into the circuitand thus enhance the image quality of the detector.

According to a preferred embodiment, the amplifier element comprises asignal input, a feedback input and a signal output. In addition, theamplifier element preferably comprises a resistive feedback element, forexample an impedance, which connects the signal output to the feedbackinput. Alternatively, the amplifier element comprises a capacitivefeedback element, for example a capacitor, or a combination composed ofa resistive and a capacitive feedback element. By combination, in thepresent context, is specifically understood a feedback element whichcomprises both a resistive and a capacitive component.

With regard to the embodiment of the amplifier element, a homogenizationof the signal properties can generally be realized via amplifierelements of known type.

According to a first embodiment variant, the actuating element ispositioned in the circuit upstream of the signal input, in particular isconnected to the signal input of the amplifier element. What is achievedby this, is a conceptually simple circuit layout and at the same time,considered in terms of circuit design, an easy balancing of thedifferent interconnect capacitances, and consequently a homogenizationof the signal properties of the output signals.

According to an alternative second embodiment variant, the alignment ofthe interconnect capacitances, and the homogenization of the signalproperties of the output signals resulting herefrom, is achieved by wayof an arrangement in which the actuating element is positioned betweenthe signal output and the feedback input of each evaluation element. Inparticular, the actuating element is arranged in the feedback element ofeach evaluation element. In the present context, a significant aspectand advantage of the second embodiment variant is to be seen in the factthat, in addition to the alignment of the interconnect capacitance, analignment of the signal properties of the output signal by way of thefeedback is made possible in each evaluation element as a result of theactuating element being arranged in the feedback element. In otherwords, owing to the arrangement of the actuating element in the feedbackelement, a more accurate alignment of the signal properties of theoutput signals is achieved compared to the arrangement in which theactuating element is positioned at the signal input of the amplifierelement. The second embodiment variant has proven advantageous inparticular with regard to the homogeneous response behavior, i.e. withregard to a homogeneous output signal for further processing by thesignal processing unit.

Preferably, the actuating element is set on the basis of a simulationand/or on the basis of a calibration process. By calibration process isto be understood for example that representative measurement signals arefed into the evaluation unit, the output signals of which are known withregard to their signal properties (in particular their pulse width). Thegenerated output signals are subsequently captured and compared in termsof their measured signal properties with the known output signals. Adeviation of the measured values for the signal properties, for examplepulse width and/or pulse height, subsequently serves for an adjustmentof the actuating element.

The setting of the actuating element by way of the simulation and/or thecalibration process is realized for example on a one-time basis in thecourse of the development and/or an (initial) commissioning of theradiation detector. Calibration data and/or setting data are stored forexample in the respective ASIC of an evaluation element. Alternatively,an alignment of the signal properties of the output signals is achievedby a suitable selection of different actuating elements.

Alternatively or in addition, the actuating element is set as a functionof temperature and/or usage, for example. In this case, in the presentcontext, in contrast to the already mentioned one-time setting, analternate setting of the actuating element is carried out with regardfor example to regions of a patient's body that are of interest to aphysician. In other words, the actuating element is set by an operator,for example as a function of the object that is to be examined, of whichimages are acquired. By object, in the present context, is understoodpreferably a human organ; alternatively, object is understood generallyas meaning an entity that is to be X-rayed, for example in the course ofa security check at an airport or in the context of an analysis of apiece of material.

Because different objects exhibit different radiation characteristicsand consequently have different energy thresholds, the setting in thealternative embodiment is carried out as a function of a likely energythreshold of the sensor signal for a scan, for example of the lung, ofthe patient. As a result, an optimal usage-specific homogenization ofthe pulse shape is achieved, and consequently an optimal image quality.The usage-specific setting of the actuating element is effected forexample in the course of each treatment preparation at the time ofpowering up or preparing the radiation detector.

Experimental measurements have revealed that the interconnectcapacitances of the electrical interconnect elements have in particulardifferent values preferably in a range between 10 fF and 10 pF, inparticular in a range of 50 fF to 1 pF, and specifically in a range of100 fF to 500 fF.

Preferably, the actuating element comprises a capacitor, for example afringe capacitor. In a cross-section, the fringe capacitor has forexample in particular a shape in the manner of two interdigitated combs.The advantage is that a simple and cost-effective implementation of thebalancing capacitance is achieved via the capacitor. Alternatively, theactuating element comprises a parallel-plate capacitor.

In order to enable the balancing of the interconnect capacitances, thecapacitors of the actuating elements are beneficially embodied and/orconfigured in such a way that they have different balancingcapacitances—analogously to the values of the interconnectcapacitances—preferably with values in a range between 10 fF and 10 pF,in particular in a range of 50 fF to 1 pF, and specifically in a rangeof 100 fF to 500 fF.

Preferably, the different balancing capacitances of the capacitors ofthe actuating elements of the evaluation elements arranged in aperipheral region of the evaluation unit have a lower value than thebalancing capacitances in a central region.

According to a beneficial development, the different balancingcapacitances of the capacitors of the actuating elements of theevaluation elements arranged in a peripheral region of the evaluationunit have a value in the range of 1 fF to 100 fF.

Analogously, the different balancing capacitances of the capacitors ofthe actuating elements of the evaluation elements arranged in a centralregion of the evaluation unit have a value in the range of 350 fF to 600fF.

This development is based on the consideration that lower capacitancevalues must be set on the part of the balancing capacitances in theperipheral region of the evaluation unit than for example in the centralregion of the evaluation unit.

Peripheral region is understood in the present context to mean a part ofthe surface area of the evaluation unit which extends from the outeredges of the evaluation unit for example in the manner of a perimetricframe in the direction of a center of the evaluation unit. For example,the peripheral region covers up to one third or up to half of the totalsurface area of the evaluation unit.

Central region is understood analogously in the present context to meanthe difference between the total surface area of the evaluation unit andthe surface area of the peripheral region.

The electrical interconnect element preferably comprises a wiringrerouting element in the manner of an interposer. By such, a technicallysimple and low-cost electrical connection is achieved between the sensorelements and the evaluation elements.

Alternatively, the sensor unit comprises an integrated wiringarrangement, for example. By integrated wiring, in the present context,is to be understood for example a wire layer having a plurality ofelectrical lines which is arranged on a surface of the sensor elementand electrically connects the sensor elements to the associatedevaluation elements.

The radiation detector is preferably embodied as a photon-counting X-raydetector. The advantage of the embodiment is to be seen in the fact thatthe already described effects (pile-up effect and paralysis effect) havea negative impact in particular in the case of photon-counting X-raydetectors. The effects are precluded, in particular in the case of anX-ray detector of such type, as a result of aligning the signalproperties of the output signals.

At least one embodiment of the invention is directed to a method foroperating a radiation detector.

FIG. 1 shows a sensor unit 4 having a plurality of sensor elements 6 andan evaluation unit 8 having a plurality of evaluation elements 10. Boththe sensor unit 4 and the evaluation unit 8 are arranged together in aradiation detector 2. In the example embodiment, the radiation detector2 is embodied as a photon-counting X-ray detector, for example as adirect converter. Radiation detectors of such type find application forexample in the medical diagnostics field for examination purposes and/orin security-sensitive areas, for example in security zones of an airportfor checking items of baggage and/or persons. During operation, theradiation detector is irradiated with X-ray radiation R. The radiationdetector is in particular part of an X-ray machine which, in addition tothe radiation detector, also comprises a radiation source (not shown inthe example embodiment).

In the example embodiment, the evaluation unit 8 is embodied as anapplication-specific integrated circuit (ASIC). This enables the circuitto be realized explicitly to cater for a specified application—in thepresent context: X-ray diagnostics.

For reasons of simplified presentation and a relevance not present forFIG. 1, an explicit depiction of the radiation detector 2 is omitted inFIG. 1.

In the example embodiment, both the sensor unit 4 and the evaluationunit 8 are embodied in the manner of an array. In this arrangement, thenumber of evaluation elements 10 corresponds to the number of sensorelements 6. Accordingly, an evaluation element 10 is associated witheach sensor element 6, as a result of which the radiation detectorcomprises a plurality (nine in the example embodiment) of sensorelement-evaluation element pairs (SAPs) 11.

To realize the electrical connection, each SAP 11 comprises anelectrical interconnect element 12. The electrical interconnect element12 has for example a strand-shaped electrical line having at least oneline element made of an electrically conductive material, for examplecopper, aluminum or tungsten, or is formed from a material of such type.Alternatively, the electrical interconnect element is embodied forexample as a conductor track on a printed circuit board. In the exampleembodiment, the SAPs 11 are electrically connected via a wiringrerouting element, in particular via an interposer 14.

In the example embodiment, the sensor unit 4 and the evaluation unit 8are each embodied as a ball-grid array (BGA), as a result of which theelectrical interconnect element 12 additionally comprises electricalinterconnect balls 16. The interconnect balls 16 are arranged in theexample embodiment in particular at terminals of the interposer 14. Inthe example embodiment, the interconnect balls 16 have a diameter with avalue in the range of 20 μm to 50 μm.

In the example embodiment, the evaluation unit 8 has a smaller surfacearea, for example by at least more than 10%, in particular by more than40%, than the sensor unit 4.

Accordingly, a length of the electrical interconnect elements 12 varieswithin the interposer 14 as a function of a local positioning of the SAP11.

The electrical interconnect elements 12 have a greater length inparticular in a peripheral region 18 of the sensor unit 4 and theevaluation unit 8 than for example in a central region 20. In theexample embodiment, the electrical connections, inclusive of the lengthof the interconnect balls 16 in the central region 22, have a lengthwith a value in the range of 10 μm to 300 μm, and in the peripheralregion 18 a length with a value in the range of 1 mm to 4 cm.

As a result of the different lengths of the electrical interconnectelements 12, the latter exhibit different parasitic effects, inparticular interconnect capacitances 22, for example parasiticcapacitances.

The interconnect capacitances 22 lead to different signal propertiesbeing exhibited by the individual output signals of the evaluation unit8. In a further processing step, for example to produce an (X-ray)image, the different signal properties result in unwanted degradationsof the image quality.

In order to align the different signal properties, in particular withregard to a pulse shape and/or a noise of the output signals, a circuitof a radiation detector 2 according to a first embodiment variant isshown in a greatly simplified block diagram in FIG. 2. In the exampleembodiment, each evaluation element 10 has such a circuit.

The circuit according to the first embodiment variant comprises thesensor unit 4, an interconnect capacitance 22, an actuating element 24,as well as an amplifier element 26 having a feedback element 28, and asignal processing unit 30. The amplifier element 26 additionallycomprises a signal input 27, a signal output 25 and a feedback input 29.In the example embodiment, the feedback element 28 connects the signaloutput 25 to the feedback input 29.

By way of explanation of the circuit, a brief description of the purposeof the circuit, in particular of the actuating element 24, is givenbelow:

In the example embodiment, the actuating element 24 comprises anadjustable capacitor, for example a fringe capacitor. Alternatively, theactuating element 24 comprises a conventional parallel-plate capacitor.

By adjustable, in the present context, is to be understood that thevalue of the capacitance of the capacitor is set, for example in thecourse of a calibration process during the commissioning of theradiation detector 2, to the interconnect capacitance 22 of therespective electrical interconnect element 12 in such a way that, due toa parallel connection of the individual capacitance 22 and of theactuating element 24, the capacitance values of the two capacitances22,24 are added together to form a common balancing capacitance value.

The setting of at least some of the remaining actuating elements 24 islikewise carried out in such a way that the same balancing capacitancevalue is produced based on a parallel connection of the two capacitances22,24. This results in the output signals of the evaluation elementsexhibiting the same signal properties, which, for example during thesubsequent processing of the output signal inside the signal processingunit 30, leads to a qualitatively more homogeneous image generation thanif the output signals were to exhibit a plurality of different signalproperties.

In the example embodiment, the actuating element 24 is arranged at, inparticular connected to, the signal input 27 for this purpose.

The amplifier element 26 is embodied for example as an operationalamplifier. Alternatively, the amplifier element is embodied as atransimpedance amplifier.

In the example embodiment, the amplifier element 26 comprises, asfeedback element 28, an impedance, for example an ohmic resistance, andin addition, in the second embodiment variant, a capacitor, for example.

In the example embodiment, the signal processing unit 30 is embodied forexample to perform the energy threshold quantification of the outputsignal.

An alignment of the signal properties of the output signals is thereforeachieved via the circuit variant shown in FIG. 2, in particular as aresult of balancing the different individual capacitances 22.

According to a second variant, an alignment of the signal properties ofthe output signals is achieved by way of an arrangement of the actuatingelement 24 inside the feedback element 28.

A greatly simplified block diagram of a circuit of a radiation detectoraccording to such a second embodiment variant is shown in FIG. 2.Analogously to the circuit illustrated in FIG. 1, the circuit shown inFIG. 2 is likewise arranged in each case as an alternative in eachevaluation element in the example embodiment.

Analogously to the embodiment illustrated in FIG. 1, the circuit of thevariant shown in FIG. 2 likewise comprises the sensor unit 4, aninterconnect capacitance 22, which has a different value as a functionof the length of the electrical interconnect element 12, the amplifierelement 26, as well as the feedback unit 28 and the signal processingunit 30.

However, according to this embodiment variant, the actuating element 24is arranged inside the feedback element 28 and is therefore connected tothe feedback input 29 of the amplifier element 26. An alignment of thesignal properties of the output signals is achieved as a result, inparticular with regard to a feedback alignment. In other words,according to the second embodiment variant, in order to align the signalproperties of the output signals, in addition to a balancing of theindividual capacitances 22, an approximation is made possible withregard to a tolerable deviation from the balancing capacitance value,provided that, in the case of a deviation from the balancing capacitancevalue (and consequently a conscious renunciation of exactly balancedinterconnect capacitances), an added value is achieved with regard tothe aligned signal properties of the output signals.

The patent claims of the application are formulation proposals withoutprejudice for obtaining more extensive patent protection. The applicantreserves the right to claim even further combinations of featurespreviously disclosed only in the description and/or drawings.

References back that are used in dependent claims indicate the furtherembodiment of the subject matter of the main claim by way of thefeatures of the respective dependent claim; they should not beunderstood as dispensing with obtaining independent protection of thesubject matter for the combinations of features in the referred-backdependent claims. Furthermore, with regard to interpreting the claims,where a feature is concretized in more specific detail in a subordinateclaim, it should be assumed that such a restriction is not present inthe respective preceding claims.

Since the subject matter of the dependent claims in relation to theprior art on the priority date may form separate and independentinventions, the applicant reserves the right to make them the subjectmatter of independent claims or divisional declarations. They mayfurthermore also contain independent inventions which have aconfiguration that is independent of the subject matters of thepreceding dependent claims.

None of the elements recited in the claims are intended to be ameans-plus-function element within the meaning of 35 U.S.C. § 112(f)unless an element is expressly recited using the phrase “means for” or,in the case of a method claim, using the phrases “operation for” or“step for.”

Example embodiments being thus described, it will be obvious that thesame may be varied in many ways. Such variations are not to be regardedas a departure from the spirit and scope of the present invention, andall such modifications as would be obvious to one skilled in the art areintended to be included within the scope of the following claims.

What is claimed is:
 1. A radiation detector, comprising: a sensor,including a plurality of sensor elements, to generate a sensor signal;an evaluation unit, including a plurality of evaluation elements, toevaluate and convert the sensor signal into an output signal; and asignal processor, directly following the evaluation unit, to process theoutput signal, wherein each of the plurality of evaluation elements isconnected to an associated one of the plurality of sensor element via arespective electrical interconnect element including an interconnectcapacitance and an individual length, respective interconnectcapacitances, of the respective electrical interconnect elements, beingdifferent from other interconnect capacitances and, as a result, leadingto different signal properties being exhibited by respective outputsignals, at least some of the plurality of evaluation elements includingan actuating element, actuating elements of different respectiveevaluation elements being different from other respective evaluationelements and being chosen to align the different signal properties ofthe output signals.
 2. The radiation detector of claim 1, wherein theactuating elements each include a balancing capacitance and whereinbalancing capacitances of different respective actuating elements aredifferent in value, from other respective actuating elements.
 3. Theradiation detector of claim 1, wherein the actuating elements areadjustable.
 4. The radiation detector of claim 1, wherein each of theevaluation elements comprises an ASIC including an amplifier element. 5.The radiation detector claim 4, wherein the amplifier element includes asignal input, a feedback input, a signal output and a feedback element,connecting the signal output to an input of the feedback input.
 6. Theradiation detector of claim 5, wherein the actuating element ispositioned upstream of the signal input.
 7. The radiation detector ofclaim 5, wherein the actuating element is arranged between the signaloutput and the feedback input.
 8. The radiation detector of claim 2,wherein the actuating element is set based upon at least one of asimulation process and a calibration process.
 9. The radiation detectorof claim 1, wherein the interconnect capacitances each have a respectivedifferent value in a range of 10 fF to 10 pF.
 10. The radiation detectorof claim 2, wherein the actuating element includes a capacitor having abalancing capacitance.
 11. The radiation detector of claim 2, whereinthe balancing capacitance has a value in the range of 10 fF to 10 pF.12. The radiation detector of claim 10, wherein the balancingcapacitance of a capacitor of one of the plurality of evaluationelements arranged in a peripheral region has a relatively lowercapacitance than the balancing capacitance of a capacitor of one of theplurality of evaluation elements arranged in a central region.
 13. Theradiation detector of claim 10, wherein at least one of the balancingcapacitance of the capacitor of one of the plurality of evaluationelements arranged in a peripheral region has a capacitance with a valuein a range of 1 fF to 300 fF, and the balancing capacitance of thecapacitor of one of the plurality of evaluation elements arranged in acentral region has a capacitance with a value in a range of 200 fF to1000 fF.
 14. The radiation detector of claim 1, wherein the electricalinterconnect elements include a wiring rerouting element.
 15. A methodfor operating a radiation detector including a sensor including aplurality of sensor elements for generating a sensor signal, anevaluation unit including a plurality of evaluation elements forevaluating and converting the sensor signal into an output signal, and asignal processing unit directly following the evaluation unit forprocessing the output signal, the method comprising: connecting each ofthe plurality of evaluation elements to an associated one of theplurality of sensor elements via a respective electrical interconnectelement, each of the respective electrical interconnect elementsincluding an interconnect capacitance and an individual length, theinterconnect capacitance of each respective electrical interconnectelement being different and leading to different signal properties beingexhibited by the respective output signals, at least some of theplurality of evaluation elements including an actuating element, whereinthe actuating element of different evaluation elements are differentfrom actuating elements of other different evaluation elements and arechosen to align the different signal properties of the output signals.16. The radiation detector of claim 1, wherein the radiation detector isan X-ray detector.
 17. The radiation detector of claim 2, wherein theactuating elements are adjustable.
 18. The radiation detector of claim2, wherein each of the evaluation elements comprises an ASIC includingan amplifier element.
 19. The radiation detector of claim 7, wherein theactuating element is arranged between the signal output and the feedbackinput in the feedback element.
 20. The radiation detector of claim 9,wherein the interconnect capacitances each have a respective differentvalue in a range between 50 fF and 1 pF.
 21. The radiation detector ofclaim 9, wherein the interconnect capacitances each have a respectivedifferent value in a range between 100 fF to 500 fF.
 22. The radiationdetector of claim 11, wherein the balancing capacitance has a value in arange between 50 fF and 1 pF.
 23. The radiation detector of claim 11,wherein the balancing capacitance has a value in a range of 100 fF to500 fF.
 24. The radiation detector of claim 12, wherein at least one ofthe balancing capacitance of the capacitor of one of the plurality ofevaluation elements arranged in a peripheral region has a capacitancewith a value in a range of 1 fF to 300 fF, and the balancing capacitanceof the capacitor of one of the plurality of evaluation elements arrangedin a central region has a capacitance with a value in a range of 200 fFto 1000 fF.
 25. The radiation detector of claim 14, wherein the wiringrerouting element is an interposer.